53 research outputs found
Square-planar copper(II) complexes with tetradentate amido-carboxylate ligands. Crystal structure of Na2[Cu(obap)]2.H2O. Strain and spectral assignments of complexes
No full textNovel N–N–N–O-type of tetradentate ligands H3obap (H3obap = oxamido-N-aminopropyl-N0-benzoic acid) and H3maeb
(H3maeb = malamido-N-aminoethyl-N0-benzoic acid) and the corresponding square-planar copper(II) complexes have been prepared
and characterized. The obap3 and maeb3 ligands coordinate to the copper(II) ion via four ligating atoms (three deprotonated
atoms: one carboxylate oxygen and two deprotonated amide nitrogens; one amine nitrogen) with in-plane square chelation. A
four coordinate, square-planar geometry has been established crystallographically for the binuclear Na2[Cu(obap)]2 Æ 2H2O complex.
Structural data correlating the square-planar geometry of the [Cu(obap)] unit and an extensive strain analysis are discussed
in relation to the information obtained for similar complexes. The infrared and electronic absorption spectra of the complexes are
discussed in comparison to the related complexes of known geometries. Antibacterial activity of ligands and copper(II) complexes
towards common Gram-negative and Gram-positive bacteria are reported as well
Square Planar copper(II) complexes with a novel tetradentate amido- carboxilate ligand. Crystal structure of [Co(H2O)6][Cu(mda)]2H2O
No full textStructural, biological and computational study of oxamide derivative|СТРУКТУРНА, БИОЛОШКА И РАЧУНСКА ИПИТИВАЊА ДЕРИВАТА ОКСАМИДА
No full textA dicarboxylato-diamide-type compound 2,2'-[(1,2-dioxoethane-1,2--diyl)diimino]dibenzoicacid (H(4)obbz) (1) was synthesized and characterized. The crystal structure of K(2)H(2)obbz center dot 2H(2)O (2) was determined by X-ray diffract-tion analysis. The cytotoxic activities of the compounds were tested against four different cancer cell lines MCF-7, A549, HT-29, HeLa and a human nor-mal cell line MRC-5. The results indicate reasonable dose-dependent cytotox-icity of the ligands that show selectivity against the tested carcinoma and healthy cell lines. Flow cytometric analysis and fluorescence microscopy showed that the most active compound, H(4)obbz, induced apoptosis and G0/G1 cell cycle arrest, indicating blockage of DNA synthesis as a possible mechanism that trig-gers apoptosis. Docking and molecular dynamics simulations gave similar res-ponses regarding interactions (binding) between their ligands and chaperon Grp78. The MMGBSA determined Delta G binding energies were in the range from -104 to -140 kJ mol(-1)
Characterization of two geometrical isomers of (1,3-propanediamine-N,N'-diacetato-N,N'-di-3-propionato)nickelate(II). X-ray structure of the binuclear complex trans(O5)-[Ni2(1,3pddadp)(H2O)4].4H2O and octahedral distortion of edta-type chelates
No full textPlasmonic Nanomembranes For Detection And Sensing
No full textNanomembranes, freestanding quasi-2D structures with thickness of the order of tens of nm and smaller and a giant aspect ratio with lateral dimensions of the order of millimeters, even centimeters, represent an important building blocks in micro and nanosystems [1], corresponding to ubiquitous bilipid membranes in living cells [2]. In this contribution we present our results in theory, design and experimental fabrication of metallic and metal-dielectric nanomembranes with plasmonic properties, intended for the use in the field of sensing. We first consider different approaches to functionalization and nanostructuring of nanomembranes [3]. These include introduction of noble metal or transparent conductive oxides fillers directly into the nanomembrane, lamination (multilayering) and patterning by 2D arrays of subwavelength nanoholes. Within this context we describe our results on nanofabrication of 8 nm thick chromium-based composite nanomembranes. Biomimetic structures utilizing nanochannel-based pores are also considered. We further present our results related to the design of chemical and biological sensors based on nanomembranes with plasmonic metamaterial properties [4]. Such sensors function as refractometric devices utilizing evanescent near fields as optical concentrators and adsorption-desorption mechanism, which ensures their ultra-high sensitivity that reaches single molecule detection [5]. We present some results on chemical sensors utilizing nanomembranes exhibiting extraordinary optical transmission, as well as those based on doublefishnet structures. Finally we consider the enhancement of infrared detectors by nanomembranes [6] utilizing the designer plasmon mechanism [7].\ud
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REFERENCES\ud
1. Jiang, C., Markutsya, S., Pikus, Y., and Tsukruk, V. V., Nature Mater., 3, 721-728 (2004).\ud
2. Matović, J., and Jakšić, Z., "Bionic (Nano)Membranes" in Biomimetics – Materials, Structures and Processes. Examples, Ideas and Case Studies, edited by Gruber, P.; Bruckner, D.; Hellmich, C.; Schmiedmayer, H.-B.; Stachelberger, H.; Gebeshuber, I. C., Berlin: Springer, 2011, pp 9-24.\ud
3. Jakšić, Z., and Matovic, J., Materials, 3, 165-200, (2010).\ud
4. Jakšić, Z., Vuković, S. M., Buha, J., and Matovic, J., J. Nanophotonics, 5, 051818 (2011)\ud
5. Jakšić, Z., Micro and Nanophotonics for Semiconductor Infrared Detectors: Towards an Ultimate Uncooled Device, Cham: Springer, 2014.\ud
6. Zijlstra, P., Paulo, P. M. R., and Orrit, M., Nature Nanotech., 7, 379-382 (2012).\ud
7. Pendry, J. B., Martín-Moreno, L., and Garcia-Vidal, F. J., Science, 305 847-848 (2004)
Cadmium, Mercury and Lead in Hypericum perforatum L. collected in Western Serbia
No full textWild population of Hypericum perforatum growing in Western Serbia was analyzed for the content of important environmental pollutants cadmium, mercury and lead. Metal contents were determined by inductively coupled plasma optical emission spectrometry. Obtained results showed that levels of mercury and lead were under while cadmium concentrations exceeded limits recommended for medicinal plants. High levels of cadmium in investigated plants can be the result of soil enriched with cadmium as well as the ability of Hypericum perforatum to accumulate cadmium
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